A hybrid vehicle has received attention as an environmentally friendly vehicle. In addition to a conventional internal combustion engine, the hybrid vehicle is equipped with a power storage device, an inverter and an electric motor driven by the inverter, as power sources for the vehicle to run. Among hybrid vehicles, a so-called plug-in hybrid vehicle allowing charging of a power storage device built in the vehicle from a power source outside the vehicle is recently attracting attention (hereinafter, the power source outside the vehicle is also referred to as an “external power source,” and charging of the power storage device in the vehicle by the external power source is also referred to as “external charging”).
Japanese Patent Laying-Open No. 2008-201262 (PTL 1) discloses a plug-in hybrid vehicle that can prevent degradation of a power storage unit in accordance with the manner of use by the user. In the hybrid vehicle, non-external charging time Tcum representing the elapsed time period from the most-recent external charging (last external charging) is continuously accumulated. When ignition is on, a map is looked up, an SOC control central value corresponding to the non-external charging time Tcum at that time point is obtained, and based on the thus obtained SOC control central value, charge/discharge of the charge storage unit is managed. If the non-external charge time Tcum exceeds a prescribed threshold value Ta, the SOC control central value increases until it reaches a control central value SOCC (N).
According to this literature, by such an arrangement, it becomes possible to prevent degradation of the charge storage unit in accordance with the style of use by the user (see PTL 1).